[PATCH] ppp: Add upstream patch to fix bounds check in EAP code.

[PATCH] ppp: Add upstream patch to fix bounds check in EAP code.

[Stefan Schantl]

[-- Attachment #1: Type: text/plain, Size: 2783 bytes --]

Signed-off-by: Stefan Schantl <stefan.schantl(a)ipfire.org>
---
 lfs/ppp                                       |  1 +
 ....8-pppd-fix-bounds-check-in-eap-code.patch | 35 +++++++++++++++++++
 2 files changed, 36 insertions(+)
 create mode 100644 src/patches/ppp/ppp-2.4.8-pppd-fix-bounds-check-in-eap-code.patch

diff --git a/lfs/ppp b/lfs/ppp
index 607765bd0..cbac95067 100644
--- a/lfs/ppp
+++ b/lfs/ppp
@@ -79,6 +79,7 @@ $(TARGET) : $(patsubst %,$(DIR_DL)/%,$(objects))
 	cd $(DIR_APP) && patch -Np1 -i $(DIR_SRC)/src/patches/ppp/0014-everywhere-use-SOCK_CLOEXEC-when-creating-socket.patch
 	cd $(DIR_APP) && patch -Np1 -i $(DIR_SRC)/src/patches/ppp/ppp-2.4.6-increase-max-padi-attempts.patch
 	cd $(DIR_APP) && patch -Np1 -i $(DIR_SRC)/src/patches/ppp/ppp-2.4.7-headers_4.9.patch
+	cd $(DIR_APP) && patch -Np1 -i $(DIR_SRC)/src/patches/ppp/ppp-2.4.8-pppd-fix-bounds-check-in-eap-code.patch
 	cd $(DIR_APP) && sed -i -e "s+/etc/ppp/connect-errors+/var/log/connect-errors+" pppd/pathnames.h
 	cd $(DIR_APP) && ./configure --prefix=/usr --disable-nls
 	cd $(DIR_APP) && make $(MAKETUNING) CC="gcc" RPM_OPT_FLAGS="$(CFLAGS)"
diff --git a/src/patches/ppp/ppp-2.4.8-pppd-fix-bounds-check-in-eap-code.patch b/src/patches/ppp/ppp-2.4.8-pppd-fix-bounds-check-in-eap-code.patch
new file mode 100644
index 000000000..858769f48
--- /dev/null
+++ b/src/patches/ppp/ppp-2.4.8-pppd-fix-bounds-check-in-eap-code.patch
@@ -0,0 +1,35 @@
+commit 8d7970b8f3db727fe798b65f3377fe6787575426
+Author: Paul Mackerras <paulus(a)ozlabs.org>
+Date:   Mon Feb 3 15:53:28 2020 +1100
+
+    pppd: Fix bounds check in EAP code
+    
+    Given that we have just checked vallen < len, it can never be the case
+    that vallen >= len + sizeof(rhostname).  This fixes the check so we
+    actually avoid overflowing the rhostname array.
+    
+    Reported-by: Ilja Van Sprundel <ivansprundel(a)ioactive.com>
+    Signed-off-by: Paul Mackerras <paulus(a)ozlabs.org>
+
+diff --git a/pppd/eap.c b/pppd/eap.c
+index 94407f5..1b93db0 100644
+--- a/pppd/eap.c
++++ b/pppd/eap.c
+@@ -1420,7 +1420,7 @@ int len;
+ 		}
+ 
+ 		/* Not so likely to happen. */
+-		if (vallen >= len + sizeof (rhostname)) {
++		if (len - vallen >= sizeof (rhostname)) {
+ 			dbglog("EAP: trimming really long peer name down");
+ 			BCOPY(inp + vallen, rhostname, sizeof (rhostname) - 1);
+ 			rhostname[sizeof (rhostname) - 1] = '\0';
+@@ -1846,7 +1846,7 @@ int len;
+ 		}
+ 
+ 		/* Not so likely to happen. */
+-		if (vallen >= len + sizeof (rhostname)) {
++		if (len - vallen >= sizeof (rhostname)) {
+ 			dbglog("EAP: trimming really long peer name down");
+ 			BCOPY(inp + vallen, rhostname, sizeof (rhostname) - 1);
+ 			rhostname[sizeof (rhostname) - 1] = '\0';
-- 
2.25.0